Set Heron as your default mail app

When Heron is your default mail app, clicking an email address link in your browser or a document (a mailto: link) opens a new message in Heron, with the recipient already filled in.

From Heron

Open Heron’s Settings (⌘ , or Ctrl ,), section On This Computer, row Heron as default email app, then click Make default. On macOS, the system may ask you to confirm. On Windows, if Heron still isn’t the default, Windows’ Default apps settings page opens so you can pick it.

mailto: links you click in an email opened in Heron always open a new message in Heron.

From your system settings

You can also do it yourself:

• macOS: open Apple’s Mail app → Mail → Settings → General → Default email reader, and pick Heron.
• Windows 11: Settings → Apps → Default apps, search for MAILTO and pick Heron. (Windows 10: Default apps → Email.)
• Linux: depending on your desktop environment, in the Default Applications settings (Mail section), or on the command line with xdg-mime if your AppImage is integrated with the system.

On iPhone, iPad and Android

• iPhone and iPad: Apple must first approve Heron as an email app (request in progress). After that, you’ll be able to pick it in Settings → Apps → Default Email App.
• Android: in Heron, Settings → Support → Heron as Default Email App opens Android’s default apps settings.

Choose the sending account

Before sending, check the From field: you can pick which mailbox sends the message there. Mailboxes are listed in your account order: see Manage your mailboxes.